[Analysis of CMV and EBV infection in healthy populations in China before and after the COVID-19 pandemic]

Objective: This study aimed to assess the infection status of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in healthy populations in China over the past decade and analyze the differences in CMV and EBV infection and related risk factors in healthy populations before and after the lifting of coronavirus disease 2019 (COVID-19) pandemic control measures. Methods: This study retrospectively analyzes the CMV and EBV infection status of 8 827 healthy donors who underwent prehematopoietic stem cell transplantation screening at Peking University People's Hospital from January 2014 to December 2023. Logistic regression analysis was conducted to determine the risk factors for CMV and EBV infection. Results: The CMV and EBV IgG positivity rates were 94.52% and 95.40% among the healthy donors, respectively, with no significant differences before and after the lifting of pandemic control measures (all P value>0.05). However, IgG antibody titers increased [CMV: (100.44±36.50) U/ml vs (109.98±36.31) U/ml, P<0.001; EBV: (281.57±226.79) U/ml vs (361.08±268.58) U/ml, P<0.001] after lifting the COVID-19 restrictions. However, the CMV IgM positivity rate remained unchanged. The EBV IgM positivity rate significantly increased after lifting measures (2.77% vs 6.29%, P<0.001), reaching 8.10% within 3 months. Further analysis of the factors affecting EBV IgM positivity revealed that gender (OR=1.479, 95% CI 1.169-1.872, P=0.001), age[compared with the group younger than 18 years, the 18-50-year age group (OR=0.584, 95% CI 0.421-0.820, P=0.002), the >50-year age group (OR=0.389, 95% CI 0.248-0.610, P<0.001) ], and the lifting of COVID-19 restrictions (OR=2.360, 95% CI 1.287-3.047, P<0.001) were independent factors influencing EBV IgM positivity in the general population. The EBV IgM positivity rate in individuals under 18 years old was not affected by gender or the lifting of COVID-19 restrictions when stratified by age group. Both genders (OR=1.499, 95% CI 1.138 - 1.975, P=0.004) and the lifting of COVID-19 restrictions (OR=2.608, 95% CI 1.940-3.507, P<0.001) were independent factors affecting EBV IgM positivity in the 18-50-year age group. The lifting of COVID-19 restrictions (OR=2.222, 95% CI 1.101-4.484, P=0.026) was the sole independent factor affecting EBV IgM positivity in individuals over 50 years old. Conclusions: Previous infection rates of CMV and EBV are high in healthy populations in China, which increase with age. COVID-19 infection may increase EBV reactivation rates in healthy individuals, with a more pronounced effect on those aged >18 years.